Gaseous electric discharge device



Nov. 8, 1938. RQMPE ET AL GASEOUS ELECTRIC DISCHARGE DEVICE Filed Sept. 13, 1937 mvzmoas Robert Rompe t M u Y E N R O U A of the device.

Patented Nov. 8, 1938 ,nsyn

PATENT oFFicE GASEOUS ELECTRIC DISCHARGE DEVICE Robert Rompe, Berlin, and Wolfgang Thom-ct, Bcrlin-ersdorf, Germany, assignors to General Electric Company, a corporation of New York- Appliwtion September 13, 1937, Serial No. 163,700

. in Germany September 15, 1936 E. or (Cl. 176-122) The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to such devices of the type comprising a spherical vessel of vitreous material containing thermionic electrodes spaced apart a distance less than the diameter of said container, a starting gas and a quantity of vaporizable metal the vapor pressure of which is.

20 atmospheres or higher during the operation The object of the invention is to provide a gaseous electric discharge lamp device of the above type which is useful in optical apparatus and has a long, useful operating life. Another object of the invention is to provide a lamp device of the above type in which the formation of light absorbing deposits of sputtered electrode material on the light transmitting walls of the container is avoided in a positive manner. Still further objects and advantages attaching to the device and to its use and operation will be apparem to those skilled in the art from the following particular description.

In accordance with these objects a gaseous electric discharge lamp device embodying the in vention comprises a vitreous container having a spherical part and a cylindrical neck part. The longitudinal axis of the neck part of the container, when prolonged, passes through the center of the spherical part thereof. A pair of thermionic electrodes are mounted in the spherical part of the container and are separated a distance substantially less than the diameter of said spherical container part. The electrodes are supported by current leads passing through the wall of the container and mounted in the same straight line; one of said electrode leads being in the longitudinal axis of the neck part of said container. A bell shaped, open-ended baflie is mounted in the neck part of the container and above the discharge path between said electrodes. The axis of said baffle is coincident with the axis of the neck part of the container. The lamp device is mounted with the electrodes in a vertical position and with the neck part of the container above the spherical part thereof. In this position the discharge between the electrodes does not deviate from the straight path between the electrodes and the sputtered particles of electrode material are carried upward into the bell-shaped tame whereby they are dethe sputtered electrode particles is thus efiectively avoided and the lamp has a long useful operating life.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in a front elevational, partly sectional view.

Referring to the drawing the gaseous electric discharge lamp device comprises a vitreous container i, such as a quartz container, having a spherical part and a cylindrical neck part. Two thermionic electrodes 2 and 3 are centrally mounted in the container i and are separated a few millimeters from each other in a vertical position. Said electrodes 2 and 3 consist of a material having high electron emission characteristics, such as alkali earth metal oxides contained in a hollow, perforated metal body, such as a perforated tungsten shell. Said container 5 has a starting gas therein, such as neon, at a pressure of about 5 mmrand a quantity of va- $0 porizable metal, such as mercuryjn such amount that it is completely vaporized during the operation of the device. Current leads 5, and a consisting of tungsten or molybdenum are fused into hard glass-or quartz tubes land 8, respectively, which in turn are fused to the container l in opposing positions so that the current leads 5 and 6 are in the same straight line.

A bell shaped baflie 9 consisting of quartz or hard glass is centrically mounted with respect to the cur- 80 rent lead 5 in the upper neck part of the condevice.

The device described above is capable of operation at mercury vapor pressures of 20 atmospheres and higher and the sputtered particles'of electrode material are swept upward from the as electrodes 2 and 3 into the bell shaped bafile or chimney 9 where they are deposited. The inner surface of the spherical part of the container 4 is thus free from light absorbing deposits of sputtered electrode material and the lamp has a 59 long useful operating life.

While we have shbwn and described and have pointed out in the annexed claim certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details oi the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention, for example, the screen 9 is supported in said container l by means of metal springs, when desired and other types of thermionic electrodes are used, when desired.

What We claim as new and desire to secure by Letters Patent of the United States, is:-'

A gaseous electric discharge lamp device oi the high vapor pressure type consisting of a vitreous container, thermionic, activated electrodes and electrode leads sealed therein, a starting gas anda quantity of mercury therein the vapor of which is luminosity producing during 'theoneration of said device, said container consisting; of a tuhu-i lar neck part and a spherical part, the longitudinal axis of said tubular part when prolonged passing through said spherical part, one oi said electrode leads being sealed into the tubular part of said container, the other of said leads being sealed into the spherical part of said container, said leads being inimovably mounted in the same straight line coincident with the longitudinal axis of the tubular container part, said leads enemas,

terminating in the spherical part oi said eontainer, each of said leads having one of said electrodes mounted thereon, the discharge path between said electrodes being in the longitudinal axis of the tubular container part, the distance between said electrodes being less than the diameter-oi the spherical part of said container, 8. bell shaped openended haille mounted in and aiilxed to the tubular part of said container and surrounding the current therein with the longitudinal axis thereof coincident with the longitudinnl axis of the tubular container part, the

' larger end 01 said haiile being above the dis- 

